White Blood Cell Differential Count (Manual Method)
This test measures the types and proportions of white blood cells in your blood, helping identify infections, immune responses, or other conditions affecting your blood cells.
["Your doctor may use this test to diagnose or monitor conditions like infections, blood disorders, or immune system issues."]
Key facts at a glance
- LOINC
- 71601-9
- Short code
- WBC Other NFr.DF Pcar Manual
- Synonyms
- WBC Other NFr.DF Pcar Manual
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 11
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- manual-count
- CPT
- 85004
- SNOMED
- 900000000000003002
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
What Does This Test Measure?
A white blood cell differential count breaks down the five main types of white blood cells (neutrophils, lymphocytes, monocytes, eosinophils, and basophils) into their individual percentages. This helps pinpoint which cells are elevated or low, which can signal different health concerns.
Why Might You Need This Test?
Doctors often order this test when you have symptoms like frequent infections, unexplained fevers, fatigue, or if you’re undergoing treatment for conditions like leukemia, lupus, or other immune disorders.
How Is the Test Performed?
A blood sample is drawn from a vein, typically in your arm. The lab then manually examines the blood smear under a microscope to count and classify each type of white blood cell.
What Are Common Results?
While exact reference ranges vary by lab, a differential count helps compare your cell types to what’s expected for your age and health. For example, high neutrophils might suggest infection, while high eosinophils could point to allergies or parasitic infections.
Reference range
Adult: 4.5-11.0 x 10^9/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test plays a critical role in diagnosing and managing conditions like infections (e.g., bacterial vs. viral), autoimmune diseases (e.g., rheumatoid arthritis), and blood cancers (e.g., lymphoma). It also helps monitor treatment effectiveness or side effects of medications.
Short name
WBC Differential (Manual)
Frequently asked questions
Why did my doctor ask for this test?
What does a high or low count of a specific white blood cell type mean?
How long does it take to get results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy